• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Hybrid+ From Digilander doesn`t work

Perhaps anyone can help me:
I bought two hybrid+ from generoso cozza. :mad:

I build the supply for the heating, and the time delay and the ps for the PowerMosfets myself and they work.

When i switch on the hybrid+, the mosfets and the resistors in front are burning.

I dont know how to adjust, and find out where the problem lies.
The only thing Mr. Generoso tells to me is: "it must work".

I should say, that i have build several mos fet amps without problems.

Can anyone help me ?


Hi Ralf,

First I should say that I have not had any experience with this kit! I have read acouple of articles about it though.

I would start by checking the voltages in the valve section and adjusting the bias pot P1. If it is burning resistors when you turn it on, I would remove the mosfets, or at lease the grid stopper resistors.

You may not be particulary interested in this at the moment, but
http://www.tubecad.com has done a review on the circuit and proposed some enhancements. If nothing else it shows the voltages in the valve section more clearly (in particular try http://www.tubecad.com/march2001/page21.html).